I have just installed a fresh copy of centos 5 and created raid 1 on 2 drives. Both my drives are 40gb but different brands. I successfully created raid 1 by following guides, which gave me this setup: RAID Devices /dev/md0 ext3 [check mark] 100 /dev/md1 swap [check mark] 1024 /dev/md2 ext3 [check mark] [remaining space] Hard Drives /dev/sda /dev/sda1 /dev/md0 software RAID [no check mark] 100 /dev/sda2 /dev/md1 software RAID [no check mark] 1024 /dev/sda3 /dev/md2 software RAID [no check mark] [remaining space] /dev/sdb /dev/sdb1 /dev/md0 software RAID [no check mark] 100 /dev/sdb2 /dev/md1 software RAID [no check mark] 1024 /dev/sdb3 /dev/md2 software RAID [no check mark] [remaining space] I also instelled grub on both drives. So everything is good the system is up and running, but I decide to test raid and unplug 1 of the drives, trying to boot only from the remaining 1. I get the grub screen, then centos startup but it gives me bad superblock, a few lines with directories that can't be found and finally a kernel panic. When i replug so both drives are on system boots fine. What am I doing wrong? I just want to make sure the system will be able to run if one drive fails. Thank you for any help guys!
What's in /boot/grub/menu.lst? Did you try this guide? http://www.howtoforge.com/software-raid1-grub-boot-fedora-8
Thank you for the guide, I actually managed to get it going by getting some ideas from the link. The main thing that stuck out to me compared to the examples was the output from cat /proc/mdstat My output differed in this line md2 : active raid1 sda3[0] 4618560 blocks [2/1] [CHUNKS] instead of md2 : active raid1 sda3[0] 4618560 blocks [2/1] [U_] So i decided to reinstall and looks like its working now, I can boot from either hard drive after installing grub on both disks. The main culprits that I can think of are: 1. It was late at night and I might of kept the last raid device as raid0 (default) instead of raid1 2. I installed kernel crash support on the initial installation which was also quoted in menu.lst from grub. This time I did not install kernel crash support Now I am getting: Personalities : [raid1] md0 : active raid1 hdb1[1] hda1[0] 200704 blocks [2/2] [UU] md1 : active raid1 hdb2[1] hda2[0] 2048192 blocks [2/2] [UU] md2 : active raid1 hdb3[1] hda3[0] 36828928 blocks [2/2] [UU] Thanx for your help, and hope that somebody stuck in the same situation can get some info from me too.
